The present invention relates to a catching head of handling apparatus suitable for catching parts such as cylinder blocks and the like.
The well-known catching head of an apparatus for handling a cylinder block comprises, as shown in FIG. 17, a cylinder 100 having connected to the plunger thereof a taper cone 101 which is to be inserted movably to and fro between metalic pawls 102 paired in such a manner that as the taper cone 101 is moved forward between the metallic pawls 102, the ends 102A of the pawls 102 are opened, and that when the taper cone 101 is moved backward between the pawls 102, the pawl ends 102A are closed. The pawl ends 102A of the metallic pawls 102 are engaged at the bottom of a cylinder block, thus catching the latter.
In such a conventional catching head of handling apparatus, the pawls are easily bent or broken, and the pawls slip and fail to catch the cylinder block in some cases. Furthermore, the pawl ends 102A are likely to damage the inner surface of the cylinder block. Also, in case the cylinder block is heavy and the metallic pawls 102 move quickly, the mechanism of the catching head of handling apparatus is disadvantageously easily broken. Moreover, such a conventional catching head of such apparatus is complicated in construction, malfunctions often and is expensive.
To catch a part which needs to be carefully handled, a catching means is known by which a flexible diaphragm such as rubber is expanded and forced into a hole formed in the part, thereby catching the latter. As shown in FIG. 18, a bag-like flexible diaphragm 103 is attached on a cylinder 104 and air is supplied through a passage 105 into the flexible diaphragm 103 which will thus be expanded to catch a part.
In the conventional catching head of handling apparatus as shown in FIG. 18, when the flexible diaphragm 103 having the end thereof introduced into a hole 107 in a thin part 106 is expanded as shown in FIG. 19, the diaphragm 103 is not securely attached to the inner circumferential surface of the hole 107, namely, the part 106 cannot be positively caught by the diaphragm 103. Also, most of such flexible diaphragms 103 use a rubber bladder formed by molding, and they cannot be greatly expanded (low in expansibility) by the air supplied into them and are poor in durability and relatively expensive. Furthermore, they are only applicable to parts of a limited range of size, and the flexible diaphragm 103 itself is relatively hard and can be used to catch only a limited range of objects to be handled.